Stacked semiconductor component having through wire interconnect (twi) with compressed wire

ABSTRACT

A semiconductor component includes a semiconductor substrate having a substrate contact, and a through wire interconnect (TWI) bonded to the substrate contact. The through wire interconnect (TWI) includes a via through the substrate contact and the substrate, a compressed wire in the via bonded to the substrate contact, and a contact on the wire. A stacked semiconductor component includes the semiconductor substrate, and a second semiconductor substrate stacked on the substrate and bonded to a through wire interconnect on the substrate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of Ser. No. 12/824,487, filed Jun. 28,2010, U.S. Pat. No. 8,193,646 B2; which is a division of Ser. No.11/859,776, filed Sep. 23, 2007, U.S. Pat. No. 7,786,605 B2; which is acontinuation of Ser. No. 11/296,057 filed Dec. 7, 2005, U.S. Pat. No.7,307,348 B2.

This application is related to Ser. No. 11/102,408, filed Apr. 8, 2005,U.S. Pat. No. 7,371,676 B2; to Ser. No. 11/743,636, filed May 2, 2007,U.S. Pat. No. 7,682,962 B2; to Ser. No. 11/743,660, filed May 2, 2007,U.S. Pat. No. 7,728,443 B2; to Ser. No. 11/743,689, filed May 3, 2007,U.S. Pat. No. 7,757,385 B2; to Ser. No. 12/703,551, filed Feb. 11, 2010,U.S. Pat. No. 7,919,846 B2; to Ser. No. 11/712,815, filed Mar. 1, 2007,U.S. Pat. No. 7,579,267 B2; to Ser. No. 11/133,085, filed May 19, 2005,U.S. Pat. No. 7,393,770 B2; to Ser. No. 12/114,757, filed May 3, 2008,U.S. Pat. No. 7,935,991 B2; to Ser. No. 12/114,761, filed May 3, 2008,U.S. Pat. No. 7,768,096 B2; to Ser. No. 12/117,919, filed May 9, 2008,U.S. Pat. No. 7,727,872 B2; to Ser. No. 12/703,520, filed Feb. 11, 2010,U.S. Pat. No. 7,951,702 B2; to Ser. No. 11/409,638, filed Apr. 24, 2006,U.S. Pat. No. 7,659,612 B2; to Ser. No. 12/581,255, filed Oct. 19, 2009,U.S. Pat. No. 7,883,908 B2; to Ser. No. 12/904,314, filed Oct. 14, 2010,U.S. Pat. No. 8,120,167 B2, to Ser. No. 13/007,743, filed Jan. 17, 2011,U.S. Pat. No. 8,053,909 B2; to Ser. No. 13/076,505, filed Mar. 31, 2011,Publication No. US 2011/0175223; and to Ser. No. 13/285,490, filed Oct.31, 2011, Publication No. 2012/0043670.

BACKGROUND

As semiconductor components become smaller and have more complicatedinput/output configurations, different types of interconnects have beendeveloped for implementing different signal transmission systems to andfrom the integrated circuits contained on the components. For example,surface interconnects, such as redistribution conductors can be formedon a particular surface, such as on a face or a back side of asemiconductor component. Via interconnects, such as metal filled vias,can be used to electrically connect electrical elements, such asterminal contacts or bond pads, on opposing surfaces of a semiconductorcomponent. Wire interconnects, such as wires bonded to bond pads, can beused to electrically connect a semiconductor component to matingcontacts on a supporting substrate, such as a package substrate, amodule substrate, or a PCB. Bump interconnects, such as solder balls orbumps, can be used to mount a semiconductor component in a flip chipconfiguration to a supporting substrate.

In fabricating semiconductor components, interconnects having a highelectrical conductivity, and a low parasitic capacitance, provide thebest performance for a signal transmission system. In addition, forfabricating semiconductor components, particularly chip scalecomponents, it is advantageous for interconnects to be capable offabrication in dense configurations using conventional equipment andtechniques. In general, conventional interconnects have limitations onconductivity, capacitance, density and manufacture. For example,deposited conductors can have a low electrical resistivity. Wireinterconnects can have a low capacitance, but require additional spacefor looping and bonding, and require protective structures such asencapsulants.

It is also advantageous for interconnects to have the capability toelectrically connect multiple semiconductor substrates in a stackedconfiguration. For example, a stacked semiconductor component caninclude multiple stacked semiconductor substrates (e.g., dice) havingintegrated circuits in a desired electrical configuration, such asmemory, processing or imaging. Conventional interconnects also havelimitations on their ability to form stacked semiconductor components.For example, wire interconnects are generally not used to makeelectrical connections between stacked substrates.

In view of the limitations of conventional interconnects, it would beadvantageous for an interconnect to have new and different featureswhich overcome some of these limitations. However, the foregoingexamples of the related art and limitations related therewith, areintended to be illustrative and not exclusive. Other limitations of therelated art will become apparent to those of skill in the art upon areading of the specification and a study of the drawings.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with components, methods, materials andsystems, which are meant to be exemplary and illustrative, not limitingin scope. In various embodiments, one or more of the above describedlimitations, have been reduced or eliminated, while other embodimentsare directed to other improvements.

A semiconductor component includes a semiconductor substrate having asubstrate contact on a first side (circuit side), an integrated circuitin electrical communication with the substrate contact, and a throughwire interconnect (TWI) bonded to the substrate contact. The throughwire interconnect (TWI) includes a via through the substrate contact andthrough the substrate to a second side (back side) thereof, a wire inthe via bonded to the substrate contact, and a contact on the wireaccessible from the second side of the substrate. A bonded connectionbetween the wire and the substrate contact can comprise a ball bond, awedge bond, a ribbon bond, or a compressed flange bond.

The through wire interconnect (TWI) also includes a bonding member onthe substrate contact and the wire, configured to secure the wire to thesubstrate contact, and provide a bonding structure for bonding to thethrough wire interconnect (TWI) to other components. The through wireinterconnect (TWI) also includes a dielectric material in the viasurrounding and electrically insulating the wire. The semiconductorcomponent can be used to fabricate stacked semiconductor components,wherein through wire interconnects (TWI) provide signal transmissionstructures, and bonding structures between adjacent stacked componentsas well.

A stacked semiconductor component includes a semiconductor substrate,and at least one second semiconductor substrate stacked on thesemiconductor substrate, and bonded to a through wire interconnect onthe semiconductor substrate. In addition, the stacked semiconductorcomponent can be constructed as an integrated system, wherein eachsemiconductor substrate performs a different electrical function in thestacked semiconductor component (e.g., memory, processing, imagingetc.). A redistribution layer RDL semiconductor component includes aterminal contact on a semiconductor substrate in electricalcommunication with a through wire interconnect on the semiconductorsubstrate.

Another stacked semiconductor component includes a plurality of stackedsemiconductor substrates having bonded through wire interconnects onadjacent substrates. A wire bonded semiconductor component includes apackage substrate, and a semiconductor substrate having a through wireinterconnect wire bonded to the package substrate. A flip chipsemiconductor component includes a package substrate, and asemiconductor substrate having a through wire interconnect flip chipbonded to the package substrate. A face to face stacked semiconductorcomponent includes two components in a face to face configuration withterminal contacts on opposing sides. A back to back stackedsemiconductor component includes two components in a back to backconfiguration with terminal contacts on opposing sides. With any stackedsemiconductor component, at least some of the through wire interconnectscan include electrically isolated substrate contacts, configured toreduce capacitance and noise on signals transmitted through the stackedsemiconductor component.

A method for fabricating a semiconductor component with a through wireinterconnect includes the steps of providing a semiconductor substratewith a substrate contact, forming a via through the substrate contactand part way through the substrate, placing the wire in the via, andbonding the wire to the substrate contact. The method also includes thesteps of placing a dielectric material in the via, thinning thesubstrate from a second side to expose at least a portion of the wire toform a contact, and forming a bonding member on the wire and thesubstrate contact.

A system for fabricating a semiconductor component includes asemiconductor substrate having an integrated circuit, a substratecontact in electrical communication with the integrated circuit. Thesystem also includes an etching system configured to form a via in thesubstrate contact and part way through the substrate. The system alsoincludes a wire bonding apparatus configured to place the wire in thevia, and to bond the wire to the substrate contact. The system alsoincludes a thinning apparatus configured to thin the semiconductorsubstrate to expose at least a portion of the wire in the via.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments are illustrated in the referenced figures of thedrawings. It is intended that the embodiments and the figures disclosedherein are to be considered illustrative rather than limiting.

FIG. 1A is a schematic plan view of a semiconductor component havingthrough wire interconnects;

FIG. 1B is a schematic side elevation view of the semiconductorcomponent of FIG. 1A;

FIG. 1C is an enlarged schematic plan view taken along line 1C of FIG.1A illustrating a through wire interconnect of the semiconductorcomponent, with a bonding member cut away to show a ball bond;

FIG. 1D is an enlarged schematic cross sectional view taken alongsection line 1D-1D of FIG. 1C illustrating a through wire interconnect;

FIG. 1E is an enlarged schematic plan view equivalent to FIG. 1C,illustrating an alternate embodiment wedge bonded through wireinterconnect on the semiconductor component;

FIG. 1F is an enlarged schematic cross sectional view taken alongsection line 1F-1F of FIG. 1E illustrating the wedge bonded through wireinterconnect;

FIG. 1G is an enlarged schematic plan view equivalent to FIG. 1C,illustrating an alternate embodiment ribbon wire through wireinterconnect on the semiconductor component;

FIG. 1H is an enlarged schematic cross sectional view taken alongsection line 1H-1H of FIG. 1G illustrating the ribbon wire through wireinterconnect;

FIG. 1I is an enlarged schematic plan view equivalent to FIG. 1C,illustrating an alternate embodiment compressed through wireinterconnect on the semiconductor component;

FIG. 1J is an enlarged schematic cross sectional view taken alongsection line 1J-1J of FIG. 1I illustrating the compressed through wireinterconnect;

FIG. 1K is an enlarged schematic plan view equivalent to FIG. 1D,illustrating an alternate embodiment wire-on-bonding-member through wireinterconnect on the semiconductor component;

FIG. 1L is an enlarged schematic plan view equivalent to FIG. 1D,illustrating an alternate embodiment double-bump through wireinterconnect on the semiconductor component;

FIG. 1M is an enlarged schematic plan view equivalent to FIG. 1D,illustrating an alternate embodiment cap-member through wireinterconnect on the semiconductor component;

FIGS. 2A-2P are schematic cross sectional views illustrating steps in amethod for fabricating a semiconductor component with a through wireinterconnect;

FIGS. 2Q-2S are schematic cross sectional views illustrating steps in amethod for fabricating a semiconductor component with a compressed wirethrough wire interconnect;

FIG. 3A is a schematic plan view taken along line 3A-3A of FIG. 2Aillustrating multiple semiconductor substrates on a wafer for performinga wafer level fabrication method;

FIG. 3B is an enlarged schematic plan view taken along line 3B-3B ofFIG. 28 illustrating an offset via configuration on a substrate contact;

FIGS. 3C-3F are enlarged schematic plan views equivalent to FIG. 3B,illustrating alternate via configurations, including multiple vias, onsubstrate contacts;

FIG. 3G is an enlarged schematic cross sectional view taken alongsection line 3G-3G of FIG. 2D illustrating a bonding wire used in thefabrication of through wire interconnects;

FIG. 3H is an enlarged schematic cross sectional view equivalent to

FIG. 3G illustrating an alternate embodiment insulated bonding wire;

FIGS. 3I and 3J are schematic cross sectional views illustratingalternate embodiment co-axial through wire interconnects;

FIG. 4A is a schematic cross sectional view of a semiconductor componentconstructed using the method of FIGS. 2A-2P;

FIG. 4B is a schematic cross sectional view of a stacked semiconductorcomponent constructed using the semiconductor component of FIG. 4A;

FIG. 5 is a schematic cross sectional view of a stacked wire bonded FBGAsemiconductor component constructed using the stacked semiconductorcomponent of FIG. 4B;

FIG. 6 is a schematic cross sectional view of a stacked flip chip bondedFBGA semiconductor component constructed using the stacked semiconductorcomponent of FIG. 4B;

FIG. 7 is a schematic cross sectional view of a stacked redistributionlayer (RDL) chip scale (CSP) semiconductor component constructed usingthe stacked semiconductor component of FIG. 4B with an added RDL layer;

FIG. 8 is a schematic cross sectional view of a four die stackedsemiconductor component;

FIG. 9 is a schematic cross sectional view of a four die stackedredistribution layer (RDL) chip scale (CSP) semiconductor component;

FIG. 10 is a schematic cross sectional view of a four die wire bondedstacked semiconductor component constructed;

FIG. 11 is a schematic cross sectional view of a four die stacked flipchip bonded semiconductor component;

FIG. 12 is a schematic cross sectional view of a two die stacked face toface semiconductor component with terminal contacts on opposing sides;

FIG. 13 is a schematic cross sectional view of a two die stacked back toback semiconductor component with terminal contacts on opposing sides;and

FIG. 14 is a schematic view illustrating a system for fabricatingsemiconductor components with through wire interconnects.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, “semiconductor component” means an electronic elementthat includes a semiconductor substrate. “Semiconductor substrate” meansan electronic element, such as a semiconductor die, or a semiconductorpackage that includes integrated circuits and semiconductor devices.“Interconnect” means an electrical element which electrically connectsdifferent electrical elements and transmits signals between theseelements. “Wafer-level” means a process conducted on an element, such asa semiconductor wafer, containing multiple semiconductor substrates.“Die level” means a process conducted on a singulated element, such as asingulated semiconductor die or package. “Chip scale” means having anoutline about the same as that of a semiconductor die. “Wafer size”means having an outline about the same as that of a semiconductor wafer.

Referring to FIGS. 1A-1D, a semiconductor component 10 (FIG. 1A) isillustrated. The semiconductor component 10 (FIG. 1A) includes asemiconductor substrate 12 (FIG. 1B) and a plurality of through wireinterconnects 14 (FIG. 1B) on the semiconductor substrate 12.

The semiconductor substrate 12 (FIG. 1B) can comprise a conventionalsemiconductor die, or a thinned semiconductor die, having integratedcircuits 22 (FIG. 1D) constructed in a desired electrical configurationusing active semiconductor devices such as transistors. For example, thesemiconductor substrate 12 (FIG. 1B) can comprise a high speed digitallogic device, such as a dynamic random access memory (DRAM), a staticrandom access memory (SRAM), a flash memory, a microprocessor, a digitalsignal processor (DSP), or an application specific integrated circuit(ASIC). In addition, the semiconductor substrate 12 (FIG. 1B) cancomprise a tested die that has been certified as a known good die.

As shown in FIG. 1A, in the illustrative embodiment, the semiconductorsubstrate 12 is a generally rectangular shaped die having opposedlateral edges and opposed longitudinal edges. However, the semiconductorsubstrate 12 (FIG. 1A) can have any polygonal shape, such as square ortriangular, and can also have a circular or oval shape. In addition, thesemiconductor substrate 12 can comprise a full thickness semiconductordie or a thinned semiconductor die. As shown in FIG. 1D, thesemiconductor substrate 12 includes a circuit side 16 (“first side” insome of the claims), and a back side 18 (“second side in some of theclaims).

As also shown in FIG. 1A, the semiconductor substrate 12 includes aplurality of substrate contacts 20 on the circuit side 16, which in theillustrative embodiment comprise the device bond pads. Alternately,rather than being the device bond pads, the substrate contacts 20 cancomprise redistribution contacts (i.e., contacts formed in conjunctionwith a redistribution layer (RDL)). In addition, the substrate contacts20 can comprise a highly-conductive, wire-bondable metal, such asaluminum or copper. The substrate contacts 20 can also comprise stacksof different metals, such as aluminum-nickel-gold,aluminum-nickel-solder, and copper-palladium.

As another alternative, at least some of the substrate contacts 20 (FIG.1A) can comprise special purpose contacts formed specifically forconstructing the through wire interconnects 14. For example, thesubstrate contacts 20 can comprise electrically isolated contacts, thatare not in electrical communication with the integrated circuits 22 onthe semiconductor substrate 12. As will be further explained, thisconcept can be employed in stacked components to reduce unwantedcapacitance, noise, bleed off voltage and bleed off current.

For simplicity, the semiconductor substrate 12 (FIG. 1A) is illustratedwith only four substrate contacts 20 (FIG. 1A) arranged in a single row.However, in actual practice the semiconductor substrate 12 (FIG. 1A) caninclude tens of substrate contacts 20 (FIG. 1A) arranged in a desiredconfiguration, such as a center array, an edge array or an area array.Also in the illustrative embodiment, the substrate contacts 20 (FIG. 1A)have a generally rectangular peripheral outline and angled corners.However, as with the semiconductor substrate 12 (FIG. 1A), the substratecontacts 20 (FIG. 1A) can have any polygonal shape including square,circular, triangular and oval. In addition, a size of the substratecontacts 20 (FIG. 1C) can be selected as required. For example, eachsubstrate contact 20 (FIG. 1C) can have a length (L) (FIG. 1C) of fromabout 50 μm to 200 μm and a width (W) (FIG. 1C) of from about 50 μm to200 μm. Also in FIG. 1A, each substrate contact 20 has an associatedthrough wire interconnect 14. However, the through wire interconnects 14can also be formed on only selected substrate contacts 20. For example,only the substrate contacts 20 having a selected output or inputconfiguration (e.g., Vss, Vcc) can be equipped with a through wireinterconnect 14.

As shown in FIG. 1D, the substrate contacts 20 can be in electricalcommunication with internal conductors 24 located within thesemiconductor substrate 12 proximate to the circuit side 16. Inaddition, the internal conductors 24 are in electrical communicationwith the integrated circuits 22 in the semiconductor substrate 12. Theinternal conductors 24 (FIG. 1D) can be part of the internal structureof the semiconductor substrate 12, and can comprise a highly conductivemetal, such as aluminum or copper. Further, a die passivation layer 26(FIG. 1D) proximate to the circuit side 16 protects the internalconductors 24 (FIG. 1D) and the integrated circuits 22 (FIG. 1D). Thedie passivation layer 26 (FIG. 1D) can comprise an electricallyinsulating material, such as BPSG (borophosphosilicate glass), a polymeror an oxide. In addition, the die passivation layer 26 (FIG. 1D)includes openings 44 (FIG. 1D) aligned with the substrate contacts 20which provide access to the substrate contacts 20. All of the elementsof the semiconductor substrate 12 including the integrated circuits 22(FIG. 1D), the internal conductors 24 (FIG. 1D), and the die passivationlayer 26 (FIG. 1D), can be formed using well known semiconductorfabrication processes.

As also shown in FIG. 1D, the through wire interconnect 14 includes avia 28 through the substrate contact 20 and the semiconductor substrate12, a wire 30 in the via 28, a bonding member 32 on the wire 30 and thesubstrate contact 20, and a dielectric material 36 in the via 28. Thevia 28 (FIG. 1D) extends through the substrate contact 20, and throughthe full thickness of the semiconductor substrate 12, from the circuitside 16 to the back side 18 thereof. In the illustrative embodiment, thevia 28 (FIG. 1D) is generally circular, and has an inside diameter (ID)which is about 1.5 to 3 times larger than the outside diameter (OD) ofthe wire 30 (FIG. 1D). By way of example, the wire 30 (FIG. 1D) can havean outside diameter (OD) of about 25 μm, and the via 28 (FIG. 1D) canhave an inside diameter (ID) of about 37.5 μm to 75 μm. In addition, alength of the via 28 (FIG. 1D) is dependent on an overall thickness T ofthe semiconductor substrate 12 (FIG. 1D). A representative range for thethickness T of the semiconductor substrate 12 (FIG. 1D) can be fromabout 10 μm to 725 μm, depending on whether the semiconductor substrate12 is a full thickness die or wafer, or a thinned die or wafer.

The via 28 (FIG. 1D) can also include an insulating layer 34 (FIG. 1D)formed on an inside diameter thereof, which electrically insulates thevia 28 (FIG. 1D) from the integrated circuits 22 (FIG. 1D), and otherelectrical elements on the semiconductor substrate 12. The insulatinglayer 34 (FIG. 1D) can comprise an electrically insulating material,such as a polymer (e.g., polyimide or parylene) or an oxide (e.g.,SiO₂). As will be further explained, the wire 30 (FIG. 1D), rather thanthe via 28 (FIG. 1D), or in addition to the via 28 (FIG. 1D), can beelectrically insulated.

In FIG. 1C, the via 28 is illustrated as being located in an upper lefthand corner of the substrate contact 20. In other words, the via 28 isoffset in both x and y directions from a center of the substrate contact20. In this case, the via 28 can have an inside diameter (ID) (FIG. 1D)that is about one half of the width (L) (FIG. 1C) of the substratecontact 20 (FIG. 1C). Alternately, as shown in FIG. 3C, a via 28A can belocated in the center 48 (FIG. 3C) of the substrate contact 20. Further,multiple vias 28B (FIG. 3D), 28C (FIG. 3E) or 28D (FIG. 3F), can beformed in the same substrate contact 20.

As shown in FIG. 1D, the wire 30 is located along a longitudinal axis 70(FIG. 2E) of the via 28, and extends across the entire length of the via28. The wire 30 (FIG. 1D) can be held in place in the via 28 (FIG. 1D)by the dielectric material 36 (FIG. 1D), which fills the via 28 (FIG.1D) and surrounds the wire 30 (FIG. 1D). In addition, the wire 30 (FIG.1D) has a first end 38 (FIG. 1D) extending out of the via 28 (FIG. 1D)and bonded to the substrate contact 20 (FIG. 1D), and a second end 40(FIG. 1D) extending just outside of the via 28 proximate to the backside 18 (FIG. 1D) of the semiconductor substrate 12.

The through wire interconnect 14 (FIG. 1D) also includes a bondedconnection 42 (FIG. 1D) between the first end 38 (FIG. 1D) of the wire30 and the substrate contact 20. In addition, the second end 40 (FIG.1D) of the wire 30 can comprise a generally spherically shaped contactball 64, such as a “free air ball” formed using an electronic flame off(EFO) process to be hereinafter described.

In the through wire interconnect 14 (FIG. 1D), the bonded connection 42(FIG. 1D) comprises a ball bond formed using a wire bonding process,such as thermosonic wire bonding. Alternately, a through wireinterconnect 14A (FIGS. 1E and 1F) can include a bonded connection 42A(FIGS. 1E and 1F) in the form of a wedge bond formed using ultrasonicwire bonding. As another alternative, a through wire interconnect 14B(FIGS. 1G and 1H) can include a ribbon wire 30B (FIGS. 1G and 1H) suchas a bonding ribbon, and a bonded connection 42B (FIGS. 1G and 1H) cancomprise a ribbon wire bond. As another alternative, a through wireinterconnect 14C (FIGS. 1I and 1J) can include a compressed wire 30C(FIGS. 1I and 1J), and a bonded connection 42C (FIGS. 1I and 1J) can bein the form of a stud bump and a compression flange on the compressedwire 30C (FIGS. 1I and 1J).

A representative outside diameter (OD) (FIG. 1D) of the wire 30 can befrom about 12 μm to about 150 μm. In addition, the wire 30 (FIG. 1D) cancomprise a conventional wire material used in semiconductor packaging,such as solder alloys, gold, gold alloys, copper, copper alloys, silver,silver alloys, aluminum, aluminum-silicon alloys, and aluminum-magnesiumalloys. In addition, the wire 30 (FIG. 1D) can comprise a metal, or ametal alloy, that does not contain reductions of hazardous substances(ROHS), such as lead. Exemplary ROHS free metals include lead freesolders, such as 97.5% Sn2.5% Ag. Other ROHS free metals include gold,copper and alloys of these metals such as copper coated with a layer offlash gold. Also, the melting point of the wire 30 (FIG. 1D) shouldpreferably be greater than that of the substrate contact 20.

As also shown in FIG. 1D, in the through wire interconnect 14, thebonding member 32 is located next to the via 28, and is bonded to thesubstrate contact 20 in a right, lower quadrant of the substrate contact20. Alternately, the bonding member 32 (FIG. 1D) can be centered on thesubstrate contact 20 (FIG. 1D) and on the via 28 (FIG. 1D), or locatedon any portion of the substrate contact 20 (FIG. 1D) or the via 28 (FIG.1D). The bonding member 32 (FIG. 1D) bonds portions of the wire 30 (FIG.1D) to the substrate contact 20 (FIG. 1D). In addition, the bondingmember 32 (FIG. 1D) functions as a securing and supporting structure forthe wire 30 (FIG. 1D), and as a bonding structure for bonding thethrough wire interconnect 14 (FIG. 1D) to an external electricalelement, such as contacts on a support substrate, or another throughwire interconnect on another semiconductor component. The bonding member32 (FIG. 1D) preferably comprises a non oxidizing, bondable materialsuch as gold or platinum, or a reflow material, such as solder.

In the illustrative embodiment, the bonding member 32 (FIG. 1D)comprises a stud bump, or a ball bump, bonded to the substrate contact20. In this case, the bonding member 32 (FIG. 1D) can be formed using awire bonder, a stud bumper, or a ball bumper. Alternately, the bondingmember 32 (FIG. 1D) can comprise a solder joint, a welded connection, ora conductive polymer connection, formed using a bonding process, such asthermal or pressure bonding to the substrate contact 20. In FIG. 1D, thebonding member 32 has a diameter which is less than the length (L) andthe width (W) of the substrate contact 20 (e.g., 25% to 75%), such thatit covers only a portion of the substrate contact 20, and does not coverthe via 28. However, as shown in FIGS. 1E and 1F, a bonding member 32Acan also be configured to substantially cover the substrate contact 20and the via 28.

Referring to FIGS. 1E and 1F, an alternate embodiment wedge bondedthrough wire interconnect 14A is substantially similar to the throughwire interconnect 14 (FIG. 1D), but includes a wire 30A (FIG. 1F) thatis wedge bonded to the substrate contact 20. In this embodiment, abonded connection 42A (FIG. 1F) between the wire 30A (FIG. 1F) and thesubstrate contact 20 comprises a wedge bond formed using an ultrasonicbonding process. In addition, the through wire interconnect 14A (FIG.1F) includes a bonding member 32A, which is substantially similar to thebonding member 32 (FIG. 1D). However, the bonding member 32A (FIG. 1E)covers almost all of the surface of the substrate contact 20 (FIG. 1E).In addition, the bonding member 32A (FIG. 1F) covers a via 28A (FIG.1F), and substantially all of the bonded connection 42A (FIG. 1F). Thethrough wire interconnect 14A also includes a dielectric material 36A(FIG. 1F) in the via 28A which secures and electrically insulates thewire 30A (FIG. 1F). In addition, the through wire interconnect 14A alsoincludes a contact 64A which comprises an exposed planar surface on anend of the wire 30A.

Referring to FIGS. 1G and 1H, an alternate embodiment ribbon wirethrough wire interconnect 14B is substantially similar to the throughwire interconnect 14 (FIG. 1D), but includes a ribbon wire 30B (FIG. 1G)in the form of a bonding ribbon. Further, a bonded connection 42B (FIG.1H) between the ribbon wire 30B (FIG. 1G) and the substrate contact 20comprises a wedge bond formed using a ribbon wire bonding process. Inaddition, the through wire interconnect 14B (FIG. 1G) includes a bondingmember 32B (FIG. 1H), which is substantially similar to the bondingmember 32 (FIG. 1D). Further, the through wire interconnect 14B (FIG.1G) includes a slot via 28S (FIG. 1FG), configured to accommodate theribbon wire 30B (FIG. 1G). The through wire interconnect 14B (FIG. 1G)also includes a dielectric material 36B (FIG. 1H) in the slot via 28A(FIG. 1G), which secures and electrically insulates the ribbon wire 30B(FIG. 1G). In addition, the through wire interconnect 14B also includesa contact 64B which comprises an exposed surface of the ribbon wire 30B.

Depending on the application, the ribbon wire 30B (FIG. 1G) can have aselected size from fine ribbon wire [13 μm×51 μm (0.5×2 mil)] to heavyribbon wire [25.4 μm×254 mm (1×10 mil)]. In addition, the ribbon wire30B (FIG. 1G) can comprise a conventional material such as gold,aluminum, silver or palladium. In general, the ribbon wire 30B (FIG. 1G)provides several advantages over round wire including high reliabilitybonded connections 42B (FIG. 1G), a high pull strength due to moresurface contact, less cratering, minimal wire sway, longer wire spans,and a planar bonding surface for the bonding member 32B (FIG. 1H). Inaddition, the ribbon wire 30B (FIG. 1G) provides a low impedance and alow inductance due to the skin effect at high frequency (i.e., currentdensity concentration in the surface layers of the conductors increaseswith frequency). Due to the skin effect, the surface area of the ribbonwire 30B (FIG. 1G) provides a larger surface area for current carryingrelative to round wire. Automatic ribbon bonders are available fromKulicke & Soffa Industries, Inc. of Willow Grove, Pa.

Referring to FIGS. 1I and 1J, an alternate embodiment compressed wirethrough wire interconnect 14C is substantially similar to the throughwire interconnect 14 (FIG. 1D), but includes a compressed wire 30C (FIG.1J) such as a stud bump, wedged into a via 28CO. In this embodiment, thesubstrate 12 has a thickness TC that is ultra thin (e.g., 10-100 μm). Inaddition, a depth of the via 28CO can be only slightly greater than aninitial diameter of the compressed wire 30C. Also in this embodiment, abonding member 32C (FIG. 1J) is formed integrally with the compressedwire 30C (FIG. 1J), and a bonded connection 42C (FIG. 1J) comprises aflanged portion of the bonding member 32C (FIG. 1J) bonded to thesubstrate contact 20. A diameter d of the bonding member 32C (FIG. 1J)is slightly greater than the inside diameter ID (FIG. 1J) of the via28CO. The compressed wire through wire interconnect 14C (FIG. 1J) alsoincludes a contact 64C which comprises an exposed surface of thecompressed wire 30C.

Referring to FIG. 1K, an alternate embodiment wire-on-bonding-memberthrough wire interconnect 14D is substantially similar to the throughwire interconnect 14 (FIG. 1D), but includes a wire 30D bonded to a topportion of a bonding member 32D. In this embodiment, a bonded connection42D is formed between the wire 30D and a top portion of the bondingmember 32D. For example, the bonding member 32D could comprise a studbump bonded to the substrate contact 20, and the bonded connection 42Dcould comprise a ball bond formed on the stud bump. Alternately, thebonded connection 42D can be formed anywhere on the bonding member 32Dsuch as in the center, or on an exterior surface thereof.

Referring to FIG. 1L, an alternate embodiment double-bump through wireinterconnect 14E is substantially similar to the through wireinterconnect 14 (FIG. 1D), but includes a double bump 32E. In thisembodiment, a bonded connection 42E comprises a wire 30E within thedouble bump 32E sandwiched between the stacked bumps of the double bump32E. Alternately, the bonded connection 42E can be formed between thelowermost bump of the double bump 32E and the substrate contact 20. U.S.Pat. Nos. 5,496,775 and 6,717,245, both of which are incorporated hereinby reference, disclose double bump structures and techniques.

Referring to FIG. 1M, an alternate embodiment cap-member through wireinterconnect 14F is substantially similar to the through wireinterconnect 14 (FIG. 1D), but includes a cap member 33F thatencapsulates a bonding member 32F and a bonded connection 42F between awire 30F and the substrate contact 20. The cap member 33F can comprisean electrically conductive material such as solder or a conductivepolymer. In this embodiment, the cap member 33F can be used as anelectrically conductive bonding structure for fabricating stackedcomponents.

Referring to FIGS. 2A-2P, steps in a method for fabricating thecomponent 10 (FIG. 1A) with through wire interconnects 14 (FIG. 1A) isillustrated. Initially, as shown in FIG. 2A, the semiconductor substrate12 is provided substantially as previously described, with the substratecontact 20, the passivation layer 26 and the internal conductor 24 inelectrical communication with the integrated circuits 22 (FIG. 1D).Alternately, rather than being electrically connected to the integratedcircuits 22 (FIG. 1D), for stacking applications, the substrate contact20 can be electrically isolated. This concept will be further explainedas the description proceeds.

In the illustrative embodiment, the method is performed at the waferlevel on a semiconductor wafer 46 (FIG. 3A) containing a plurality ofsemiconductor substrates 12. However, it is to be understood that themethod of the invention can be performed at the die level on singulatedsubstrates, such as singulated bare dice and known good dice (KGD). Alsoin the illustrative embodiment, the semiconductor wafer 46 (FIG. 3A)comprises a semiconductor material, such as silicon or gallium arsenide.In addition, the semiconductor substrates 12 (FIG. 3A) are in the formof semiconductor dice having a desired electrical configuration, such asmemory, application specific, or imaging and image sensing. However, itis to be understood that the method of the invention can be performed onother substrates including ceramic, plastic, tape, printed circuit board(PCB), metal lead frame, or flex circuit substrates. As shown in FIG.2A, the semiconductor substrate 12 includes the circuit side 16 with thesubstrate contacts 20 and die passivation layer 26 thereon, and the backside 18.

Next, as shown in FIG. 2B, the vias 28 are formed through the substratecontacts 20, but only part way through the substrate 12. The vias 28 canbe formed using an etching process, a laser machining process, an ionmilling process, a mechanical process (e.g., drilling, grinding,abrasion), or combinations of any of these processes. For example, thevias 28 can be formed using a dry etch process, such as a reactive ionetching (RIE) through a mask, such as a photo mask or a hard mask,having openings, which locate the vias 28 on the substrate contacts 20.In this case, a first etch gas can be used to etch through the substratecontacts 20, and a second etch gas can be used to etch part way throughthe semiconductor substrate 12. In addition, parameters (e.g., time,temperature, etchant) of the dry etch process can be controlled suchthat a depth “D” of the vias 28 (FIG. 2B) is endpointed within thesemiconductor substrate 12 at a distance “S” (FIG. 2B) from the backside 18. With the wafer 46 and the semiconductor substrate 12 comprisingsilicon, reactive ion etching (RIE) can be performed in a reactor withan etch gas, such as CF₄, SF₆, Cl₂ or CCl₂F₂. Reactive ion etching (RIE)is sometimes referred to as “BOSCH” etching, after the German companyRobert Bosch, which developed the original process.

Another method for forming the vias 28 (FIG. 2B) combines etching andlaser machining processes. For example, an etch mask (not shown) and anetching process can be used to form the vias 28 through the substratecontacts 20. Depending on the material of the substrate contacts 20, awet etchant can be used. For substrate contacts 20 made of aluminum, onesuitable wet etchant is H₃PO₄. Following etching through the substratecontacts 20, a laser machining process can be used to form the vias 28part way through the semiconductor substrate 12. One suitable lasersystem for performing the laser machining step is manufactured by XSILLTD of Dublin, Ireland, and is designated a Model No. XISE 200. Anothersuitable laser system for performing the laser machining step ismanufactured by Electro Scientific, Inc., of Portland, Oreg. and isdesignated a Model No. 2700. Following the laser machining step, acleaning step can be performed in which the vias 28 (FIG. 2B) arecleaned using a suitable wet or dry etchant. One suitable wet etchantwith the semiconductor substrate 12 (FIG. 2B) comprising siliconcomprises tetramethylammoniumhydroxide (TMAH). U.S. Pat. No. 6,620,731,to Farnworth et al. which is incorporated herein by reference, furtherdescribes methods for forming the vias 28 (FIG. 2B).

As shown in FIG. 3B, in the illustrative embodiment the vias 28 areoffset in x and y directions from the centers 48 of the substratecontacts 20. This arrangement provides the most surface area on thesubstrate contacts 20 available for subsequently forming the bondedconnections 42 (FIG. 1C). As shown in FIG. 3C, the vias 28A canalternately be formed through the centers 48 of the substrate contacts20. In this case, the bonded connections 42A (FIG. 1F) can be radiallyoffset from the centers 48 of the substrate contacts 20. As shown inFIG. 3D, two vias 28B can also be formed on each substrate contact 20for forming two through wire interconnects on each substrate contact 20.As shown in FIG. 3E, three vias 28C can also be formed on each substratecontact 20 for forming three through wire interconnects on eachsubstrate contact 20. As shown in FIG. 3F, four vias 28D can also beformed on each substrate contact 20 for forming four through wireinterconnects on each substrate contact 20.

Next, as shown in FIG. 2C, the insulating layers 34 can be formed in thevias 28. The insulating layers 34 can comprise a polymer, such aspolyimide or parylene, deposited using a suitable process, such as vapordeposition, capillary injection or screen-printing. Alternately, theinsulating layers 34 can comprise a deposited oxide layer, such as a lowtemperature deposited oxide. As another alternative, the insulatinglayers 34 can comprise a grown oxide layer, such as silicon dioxideformed by oxidation of silicon.

As also shown in FIG. 2C, a vent 50 can be formed from the back side 18of the semiconductor substrate 12 into each via 28. The vents 50 (FIG.2C) can be formed using a laser machining process, and the previouslydescribed laser systems. Alternately, the vents 50 (FIG. 2C) can beformed using an etching process performed from the back side 18 of thesemiconductor substrate 12. As will be further explained, the vents 50(FIG. 2C) allow the wire 30 (FIG. 1D) and the dielectric material 36(FIG. 1D) to be more easily placed in the via 28 (FIG. 2C). For example,the vents 50 provide a pressure differential for venting trapped gasesfrom the via 28 during placement of the wire 30 (FIG. 1D) and duringdeposition of the dielectric material 36 (FIG. 1D). In addition, thevents 50 help to draw and seat the wires 30 (FIG. 1D) in vias 28. Thevents 50 (FIG. 1D) also provide capillary action under a vacuum fordepositing the dielectric material 36 into the vias 28. Preferably, thevents 50 (FIG. 2C) have a diameter that is less than the diameter of thewires 30 (FIG. 1D). In addition, the diameter of the vents 50 (FIG. 2C)can be selected to provide seats for the second ends 40 of the wires 30.A representative diameter of the vents 50 (FIG. 2C) can be from 5 μm to15 μm. In FIG. 2C, the vents 50 are tapered from the back side 18 of thesemiconductor substrate 12, as would occur with a laser machiningprocess, wherein lasered openings are larger at the point of entry.

Next, as shown in FIG. 2D, a wire bonder 52 having a bonding capillary54 can be provided. Preferably the wire bonder 52 is configured toperform an ultra fine pitch (e.g., <65 μm) wire bonding process.Suitable wire bonders are manufactured by Kulicke & Soffa IndustriesInc. of Willow Grove, Pa., and Palomar of Carlsbad, Calif. One suitablewire bonder is a model “8098” large area ball bonder manufactured byKulicke & Soffa Industries Inc., having a total bond placement accuracyof about +/−5 μm at pitches down to about 65 μm. Bonding capillaries areavailable from SPT (Small Precision Tools) of Petaluma, Calif., and fromKulicke & Soffa Industries Inc.

The wire bonder 52 (FIG. 2D) and the bonding capillary 54 are configuredto form a continuous length of bonding wire 58 into the wire 30 (FIG.1D) for the through wire interconnect 14 (FIG. 1D). The bonding wire 58can comprise a conventional wire material used in semiconductorpackaging, such as the previously identified materials for the wire 30(FIG. 1D). As shown in FIG. 3G, the bonding wire 58 can be generallycircular in cross section with an outside diameter (OD) selected toallow placement of the wire 58 into the via 28. A representative rangefor the outside diameter (OD) of the bonding wire 58 can be from about12 μm to about 150 μm. As shown in FIG. 3H, an alternate embodimentinsulated bonding wire 58A includes an electrically insulating outerlayer 78, such as a polymer. The insulating layer 78 on the bonding wire58 can take the place of the insulating layers 34 (FIG. 1D) in the vias28 (FIG. 1D). This type of bonding wire 58A is available from Micro Bondof Canada.

As shown FIG. 3I, the insulated bonding wire 58A can be used to form aco-axial through wire interconnect 14CA-1. The co-axial through wireinterconnect 14CA-1 (FIG. 3I) includes a via 28CA (FIG. 3I) through thesubstrate contact 20 and an insulating layer 34CA (FIG. 3I) on the via28CA (FIG. 3I) substantially as previously described for the via 28(FIG. 1D) and the insulating layer 34 (FIG. 1D). The co-axial throughwire interconnect 14CA-1 also includes a dielectric material 36CA, whichsecures the insulated bonding wire 58A (FIG. 3I) in the via 28CA (FIG.3I) substantially as previously described for dielectric material 36(FIG. 1D). The co-axial through wire interconnect 14CA-1 also includes aco-axial conductor 31CA (FIG. 3I), which comprises an additional metallayer on the insulating layer 34CA (FIG. 3I). The co-axial conductor 31CA (FIG. 3I) forms a shield which confines radiation formed by atransverse electromagnetic (TEM) wave during transmission ofelectromagnetic signals through the wire 58A (FIG. 3I). The co-axialthrough wire interconnect 14CA-1 (FIG. 3I) can also be used to transmitfirst signals through the wire 58A (FIG. 3I), and to transmit secondsignals through the co-axial conductor 31 CA (FIG. 3I).

As shown in FIG. 3J, an alternate embodiment co-axial through wireinterconnect 14CA-2 is substantially similar to the co-axial throughwire interconnect 14CA-1 (FIG. 3I), but includes the wire 30(un-insulated as previously described), and an additional insulatinglayer 35CA on the co-axial conductor 31CA (FIG. 3J). Again, the co-axialconductor 31CA (FIG. 3J) forms a shield which confines radiation formedby a transverse electromagnetic (TEM) wave during transmission ofelectromagnetic signals through the wire 30 (FIG. 3I). The co-axialthrough wire interconnect 14CA-2 (FIG. 3J) also allows first signals tobe transmitted through the wire 30 (FIG. 3J), and second signals to betransmitted through the co-axial conductor 31 CA (FIG. 3I).

Referring to FIG. 2D, the bonding capillary 54 is movable in x, y and zdirections responsive to signals from a controller 80 of the wire bonder52. The bonding capillary 54 includes an elongated opening 60 having aninside diameter about twice the diameter of the bonding wire 58, and anenlarged, chamfered terminal portion. The wire bonder 52 also includeswire clamps (not shown) operably associated with the bonding capillary54, which are configured to open and close about the bonding wire 58responsive to signals from the controller 80. U.S. patent applicationSer. No. 11/102,408, filed on Apr. 8, 2005, which is incorporated hereinby reference, provides further details of the wire bonder 52 and thebonding process to be hereinafter described.

As shown in FIG. 2D, the wire bonder 52 also includes an electronicflame off (EFO) wand 56 configured to generate an electronic spark 62for forming the contact ball 64 on a terminal portion of the bondingwire 58. The contact ball 64 will subsequently form the first end 38(FIG. 1D) of the wire 30. The contact ball 64 is also known in the artas a “free air ball” (FAB). A diameter of the contact ball 64 will bedependent on the diameter of the bonding wire 58, with from 1.5 to 4times the diameter of the bonding wire 58 being representative.

Next, as shown in FIG. 2E, an alignment step can be performed in whichthe bonding capillary 54 is aligned with the via 28. The alignment stepcan be performed using an automated alignment system 82 (FIG. 2D) of thewire bonder 52 (FIG. 2D). In addition, the semiconductor wafer 46 (FIG.3A) with the semiconductor substrates 12 thereon, can be placed on awork holder 68 (FIG. 2E) of the wire bonder 52 (FIG. 2D). During thealignment step, the position of the via 28 (FIG. 2E) can be ascertainedby the automated alignment system 82 of the wire bonder 52, and thebonding capillary 54 can be moved in x and y directions, such that thecenter of the contact ball 64 aligns with the longitudinal axis 70 (FIG.2E) of the via 28. Also during the alignment step, the bonding capillary54 can be operated to position the bonding wire 58 such that a terminalportion of the bonding wire 58 has a desired tail length TL (FIG. 2E).The tail length TL can be selected to be slightly greater (e.g., 1 toseveral microns) than the depth D (FIG. 2B) of the via 28 (FIG. 2E).

Next, as shown in FIG. 2F, a placing step can be performed in which thebonding capillary 54 is moved in a z-direction, as indicated by arrow76, to place the tail length TL of the bonding wire 58 into the via 28.In addition, the placing step can be performed such that the contactball 64 contacts a bottom surface 74 (FIG. 2F) of the via 28. During theplacing step, the vent 50 (FIG. 2F) helps to maintain a positive air orgas flow through the via 28, which facilitates placement of the taillength TL (FIG. 2E) of the bonding wire 58 into the via 28. In addition,the vent 50 can be formed with a surface which seats the contact ball 64on the bottom surface 74 (FIG. 2F) of the via 28. As an alternative tomoving the bonding capillary 54 (FIG. 2F) in the z-direction, theplacing step can be performed by maintaining the bonding capillary 54 ina stationary position over the via 28, and then spooling the bondingwire 58 into the via 28.

Next, as shown in FIG. 2G, a looping step can be performed in which thewire clamps (not shown) of the wire bonder 52 (FIG. 2D) are opened, andthe bonding capillary 54 is moved in x and z directions (and also in they direction if required) into a position on the substrate contact 20 formaking the bonded connection 42 (FIG. 2H). The looping step can beperformed using the alignment system 82 (FIG. 2D) of the wire bonder 52(FIG. 2D). In this case, the controller 80 (FIG. 2D) of the wire bonder52 (FIG. 2D) can be loaded with information on the desired locations ofthe bonded connections 42 (FIG. 2H).

Next, as shown in FIG. 2H, a bonding step can be performed in which thebonded connection 42 is formed on the substrate contact 20. In theillustrative embodiment, the bonded connection 42 comprises a ball bondformed using thermosonic by the bonding capillary 54. Alternately, aswill by further explained, the bonded connection 42 can comprise a wedgebond, a ribbon wire bond, or a flanged portion of the bonding member 32.The bonded connection 42 can also comprise a reflow, welded,metallurgical, mechanical or polymer connection formed using anysuitable process known in the art.

Next, as shown in FIGS. 2I and 2J, a severing step can be performed inwhich the wire clamps of the wire bonder 52 (FIG. 2D) are closed, andthe bonding capillary 54 is moved as indicated by arrow 84 (FIG. 21) tosever the bonding wire 58 from the bonded connection 42. FIG. 2Jillustrates the resultant wire 30 of the through wire interconnect 14(FIG. 1D). The wire 30 (FIG. 2J) includes the first end 38 (FIG. 2J)having the bonded connection 42 (FIG. 2J) in the form of a ball bond onthe substrate contact 20. The wire 30 (FIG. 2J) also includes the secondend 40 (FIG. 2J) having a contact in the form of the contact ball 64,which is preferably seated in the via 28 in contact with the bottomsurface 74 thereof.

Next, as shown in FIG. 2K, a dielectric fill step can be performed inwhich the dielectric material 36 is deposited into the via 28 in viscousform and then cured to harden. The dielectric material 36 can comprisean electrically insulating curable polymer, such as a polyimide, anepoxy or a silicone. Also, the dielectric material 36 (FIG. 2K) caninclude fillers, such as silicates, configured to reduce the coefficientof thermal expansion (CTE) and adjust the viscosity of the dielectricmaterial. Suitable curable polymers are manufactured by Shinitsu ofJapan, and Dexter Electronic Materials of Rocky Hill, Conn. Followingcuring, the dielectric material 36 (FIG. 2K) provides a pottingstructure which secures and electrically insulates the wire 30 in thevia 28.

The dielectric material 36 (FIG. 2K) can be injected into the via 28 ina viscous state, pulled by capillary action by vacuum directed throughthe vent 50, and then cured. For example, a positive displacementmechanism such as a syringe, can be used to dispense a quantity of thedielectric material 36 (FIG. 2K) into the via 28. One suitable nozzledeposition apparatus, also known as a material dispensing system, ismanufactured by Asymtek of Carlsbad, Calif. Other suitable depositionprocesses for depositing the dielectric material 36 (FIG. 2K) into thevia 28 include screen printing, stenciling and stereographiclithography.

Next, as shown in FIG. 2L, a dielectric removal step can be performed tosubstantially remove the dielectric material 36 from the substratecontact 20. The dielectric removal step can be performed using an etchprocess, such as reactive ion etching (RIE), plasma etching or wetetching. With an etch process an etchant, strips or cleans the excessdielectric material 36 from the substrate contact 20.

Next, as shown in FIG. 2M, a bonding member forming step can beperformed in which the bonding member 32 is formed on the substratecontact 20 and on a portion of the wire 30. The bonding member formingstep can be performed to position the bonding member 32 on a desiredportion of the substrate contact 20. In addition, the bonding member 32can be offset with respect to the via 28 or centered on the via 28. Asanother alternative, and as shown in FIGS. 1E and 1F, a bonding member32A can cover the entire substrate contact 20.

Preferably, the bonding member 32 (FIG. 2M) comprises a non oxidizingeasily bondable material, such as gold or platinum. The bonding member32, in addition to providing an external bonding element for the throughwire interconnect 14 (FIG. 1D), also secures the wire 30 in the via 28,and provides a security bond for the bonded connection 42. In theillustrative embodiment, the bonding member 32 comprises a stud bump ora ball bump, formed using a wire bonder, a stud bumper or a ball bumper.For example, a bonding capillary similar to the bonding capillary 54 canbe used to form a stud bump. As another example, a suitable stud bumperis a “WAFER PRO PLUS” high speed large area stud bumper manufactured byKulicke & Soffa Industries Inc. of Willow Grove, Pa. As another example,suitable solder ball bumpers are manufactured by Pac Tech PackagingTechnologies of Falkensee, Germany.

In the embodiment illustrated in FIG. 2M, the bonded connection 42 hasbeen made, and the bonding member 32 has been placed on the bondedconnection 42. However, the bonding member 32 can also be bonded to thesubstrate contact 20 first, and then the end 38 of the wire 30 bonded tothe bonding member 32 second. In the case, the bonded connection 42 canalso be located on any portion of the bonding member 32, such as on thetop surface thereof, rather than on the lower surface thereof as in FIG.2M. The through wire interconnect 14D (FIG. 1K) illustrates one sucharrangement wherein the bonded connection 42D is formed on the bondingmember 32D. Double bumping or stacked bumping techniques can also beused to form the bonding member 32. For example, the through wireinterconnect 14E (FIG. 1L) illustrates the double bump bonding member32E (FIG. 1L).

Next, as shown in FIG. 2N, a backside thinning step can be performed inwhich the semiconductor substrate 12 is thinned from the back side 18,such that the via 28 is opened, and the contact ball 64 is exposed. Ingeneral, the backside thinning step can be performed to expose anyportion of the wire 30 which can be used as a contact for making anelectrical connection from the outside to the through wire interconnect14. The backside thinning step can be performed such that the thinnedsubstrate 12 has a thickness of T. A representative range for thethickness T can be from about 10 μm to 725 μm. During the thinning step,and in subsequent steps to follow, the semiconductor wafer 46 (FIG. 3A)can be mounted in a temporary carrier (not shown). For example,temporary carriers made of glass can be fused by heat and adhesives tothe semiconductor wafer 46 (FIG. 3A) to protect the circuit side 16(FIG. 3A) of the semiconductor substrate 12. Suitable, temporarycarriers are manufactured by 3-M Corporation of St. Paul, Minn., andothers as well. As another alternative, for some steps of the method,the circuit side 16 of the wafer 46 (FIG. 3A) can be protected by aremovable material such as a tape or mask material applied to thesemiconductor wafer 46.

The backside thinning step of FIG. 2N, can be performed using a chemicalmechanical planarization (CMP) apparatus. One suitable CMP apparatus ismanufactured by “ACCRETECH” of Tokyo, Japan, and is designated a modelno. “PG300RM”. Suitable CMP apparatus are also commercially availablefrom Westech, SEZ, Plasma Polishing Systems, TRUSI and othermanufacturers. The backside thinning step can also be performed using anetching process, such as a wet etching process, a dry etching process ora plasma etching process. As another alternative, a combination ofplanarization and etching can be performed. For example, a mechanicalgrinder can be used to remove the bulk of the material, followed byetching to remove grind damage. U.S. Pat. No. 6,908,784, which isincorporated herein by reference, further describes processes andequipment for performing the backside thinning step.

Next, as shown in FIG. 2O, an optional back side insulating step can beperformed in which an insulating layer 86 is formed on the thinnedbackside 18 of the semiconductor substrate 12. The insulating layer 86can comprise a polymer layer such as polyimide or parylene, a glass suchas BPSG, or an oxide such as silicon dioxide. In addition, theinsulating layer can be formed using a suitable deposition process suchas CVD, screen printing or taping. Further, the insulating layer 86includes openings 88 which align with the contact balls 64.

Next, as shown in FIG. 2P, an optional polymer button forming step canbe performed in which polymer buttons 90 are formed on the contact balls64. The button forming step can be performed using a suitable polymer,such as a silicone, a polyimdie or an epoxy, and a process such asnozzle deposition or screen printing. Depending on the application, thepolymer buttons 90 (FIG. 2P) can provide electrical insulation andprotection, an adhesive connection, or an electrical connection. If noelectrical contact is made to the contact ball 64 (FIG. 2P), the polymerbuttons 90 can comprise an electrically insulating material.Alternately, the polymer buttons 90 (FIG. 2P) can comprise anelectrically conductive material, such as an anisotropic adhesive. Theadhesive buttons 90 can also comprise an adhesive material forapplications such as stacking and surface mounting.

Next, a singulating step, such as sawing, scribing, liquid jetting, orlaser cutting through a liquid, can be performed to singulate a chipscale semiconductor component 92 (FIG. 4A) from the wafer 46.Alternately, a wafer sized component can be provided which containsmultiple unsingulated semiconductor substrates 12.

Referring to FIGS. 2Q-2T, steps in a method for forming the compressedwire through wire interconnect 14C (FIG. 1J) are illustrated. Initially,as shown in FIG. 2Q, the substrate 12, the substrate contact 20 and thebonding capillary 54 are provided, as previously described. In addition,the via 28CO is formed in the substrate 12 as previously described.However, in this case the depth d of the via 28CO is very small, on theorder of from 10 μm to 125 μm. Preferably, the outside diameter OD ofthe contact ball 64 of the bonding wire 58 is approximately equal to thedepth d of the via 28CO, and to the inside diameter ID of the via 28CO.In this embodiment, it is preferable to compress the contact ball 64into the via 28CO, and to fill the via 28CO with the metal of thecontact ball 64.

Next, as shown in FIGS. 2R and 2S, the bonding capillary 58 is operatedto compress the contact ball 64 and the bonding wire 58 into the via28CO, forming the compressed wire 30C, the bonded connection 42C (FIG.2S) and the bonding member 32C (FIG. 2S). As shown in FIG. 2T, followinga substrate thinning step as previously described, the contact 64C onthe compressed wire 30C is exposed. Alternately, rather than using thebonding capillary 54, the compressed through wire interconnect 14C canbe fabricated by depositing a metal into the via 28CO and thencompressing the metal using a tamping tool.

As shown in FIG. 4A, a chip scale semiconductor component 92 includesthe semiconductor substrate 12 having a plurality of through wireinterconnects 14, which correspond to the locations of the substratecontacts 20. The substrate contacts 20 can have any desiredconfiguration including dense area arrays, such as edge arrays, centerarrays, or perimeter arrays. The through wire interconnects 14 can beused as terminal contacts, which can be surface mounted to a supportingsubstrate, or stacked to other components. In addition, the bondingmembers 32 provide electrical connection points proximate to the circuitside 16, and the contact balls 64 provide electrical connection pointsproximate to the back side 18 of the semiconductor substrate 12.

Referring to FIG. 4B, a stacked semiconductor component 94 includes thesemiconductor component 92, and a bumped semiconductor die 96 stacked onthe semiconductor component 92. The bumped semiconductor die 96 cancomprise a full or partial thickness die, having a plurality of bumpedcontacts 98 (e.g., stud bumps or ball bumps) on a circuit side 102thereof, in electrical communication with the integrated circuitscontained on the semiconductor die 96. In addition, the bumped contacts98 can be arranged in an area array, which corresponds to the area arrayof the through wire interconnects 14 on the semiconductor component 92.Further, the bumped contacts 98 can be bonded to the contact balls 64 ofthe through wire interconnects 14 on the semiconductor component 92.

The bumped contacts 98 (FIG. 4B) can comprise a bondable metal such asgold, platinum or solder, or a conductive polymer, such as metal filledepoxy, which can be bonded to the contact balls 64 using a suitableprocess such as diffusion bonding, thermal bonding or reflow bonding.For example, the bumped contacts 98 can comprise gold stud bumps, andthe contact balls 64 can comprise gold free air balls, such that a goldto gold diffusion bond can be formed. Further, an adhesive layer 100(FIG. 4B), such as a curable polymer underfill material, adhesivelybonds the circuit side 102 (FIG. 4B) of the semiconductor die 96 (FIG.4B) to the back side insulating layer 86 on the semiconductor component92.

The stacked semiconductor component 94 (FIG. 4B) can be fabricated atthe wafer level with a plurality of semiconductor dice 96 contained on awafer, and the singulated components 92 then bonded to the semiconductordice 96 on the wafer. In this case, a die attacher or an aligner bondercould be employed to place and bond the semiconductor components 92 tothe semiconductor dice 96 contained on the wafer. In addition, thecomponents 92 can be tested prior to the bonding process and certifiedas known good components (KGC) to improve the yield of the bondingprocess. Following the bonding process, the stacked semiconductorcomponents 94 could be singulated from the wafer containing thesemiconductor dice 96 with the semiconductor component 92 bondedthereto. Alternately, the semiconductor dice 96 and the semiconductorcomponents 92 could both be singulated components. As anotheralternative, a wafer to wafer fabrication process could be employedwherein both the semiconductor dice 96 and the semiconductor components92 are contained on mating wafers.

As mentioned previously, at least some of the substrate contacts 20(FIG. 4B) on the stacked semiconductor component 94 (FIG. 4B) can beelectrically isolated, and not in electrical communication with theintegrated circuits 22 (FIG. 1D) on the semiconductor substrate 12. Inthis case, electrical signals can be transmitted through the stackedsemiconductor component 94 (FIG. 4B) without adding unwanted inductanceor capacitance. For example, the semiconductor substrate 12 (FIG. 4B) ofthe semiconductor component 92 (FIG. 4B) can comprise a dynamic randomaccess memory (DRAM). The DQ circuits on some DRAM's have up to 1 pf ofcapacitance added into the DQ circuits, to help offset the inductanceadded to the DRAM by wire bonds. In general, wire bonds have a highinductance but very low capacitance.

In the stacked component 94 (FIG. 4B) capacitance could potentially beadded each time a signal is transmitted through a substrate contact 20(FIG. 4B) associated with a DQ circuit. Similarly, noise, bleed offvoltage, and bleed off current could potentially be added to the signalstransmitted through the through wire interconnects 14 (FIG. 4B).However, if selected substrate contact 20 are electrically isolated fromthe integrated circuits 22 (FIG. 1D) as required, parasitics could bereduced. One method for electrically isolating a substrate contact 20(FIG. 4B) would be to etch or laser machine a trench around theperimeter of the substrate contact 20 (FIG. 4B). Another method would beto incorporate programmable links, such as fuses, antifuses or gates,between the substrate contacts 20 (FIG. 1D) and the integrated circuits22 (FIG. 1D). Yet another method would be to design and fabricate thesubstrate contact 20 as an electrically isolated pass through contactfor stacking applications.

Referring to FIG. 5, a wire bonded fine ball grid array (FBGA)semiconductor component 104 includes the stacked semiconductor component94 wire bonded in a board on chip (BOC) configuration to a packagesubstrate 106. The package substrate 106 includes a plurality ofterminal contacts 108, such as solder balls, in a fine ball grid array.The terminal contacts 108 are in electrical communication with wirebonding pads 118 on the package substrate 106. In addition, the packagesubstrate 106 includes a wire bonding opening 116, and a plurality ofwires 110 that are wire bonded to the wire bonding pads 118 on thepackage substrate 106, and to the bonding members 32 on the through wireinterconnects 14 of the semiconductor component 92. The wire bonded fineball grid array (FBGA) semiconductor component 104 also includes apackage encapsulant 112 on the package substrate 106, which encapsulatesthe stacked semiconductor component 94, and a wire bond encapsulant 114,which encapsulates the wires 110 and associated wire bonds.

Referring to FIG. 6, a flip chip bonded (FCIP) fine ball grid array(FBGA) semiconductor component 120 includes the stacked semiconductorcomponent 94 flip chip bonded in a chip on board (COB) configuration toa package substrate 122. The package substrate 122 includes a pluralityof terminal contacts 124, such as solder balls, in a fine ball gridarray. The terminal contacts 124 are in electrical communication withflip chip bonding pads 128 on the package substrate 122. In addition,the bonding members 32 on the through wire interconnects 14 of thesemiconductor component 92 are flip chip bonded to the flip chip bondingpads 128 on the package substrate 122. The semiconductor component 120also includes the package encapsulant 112 on the package substrate 122,which encapsulates the stacked semiconductor component 94.

Referring to FIG. 7, a redistribution layer (RDL) chip scale (CSP)semiconductor component 130 is substantially similar to the stackedsemiconductor component 94 (FIG. 4B). However, the redistribution layer(RDL) chip scale (CSP) semiconductor component 130 also includesterminal contacts 132, such as solder balls in an area array. Theterminal contacts 132 are in electrical communication withredistribution layer conductors 134 formed on the circuit side 16 of asemiconductor component 92RDL. The semiconductor component 92RDL issubstantially similar to the semiconductor component 92 (FIG. 4A) butalso includes the redistribution layer conductors 134 in electricalcommunication with the bonding members 32 of the through wireinterconnects 14. The redistribution layer conductors 134 can befabricated at the wafer level on the semiconductor wafer 46 (FIG. 3A)containing the semiconductor component 92.

Referring to FIG. 8, a four die stacked semiconductor component 136 issubstantially similar to the stacked semiconductor component 94 (FIG.4B). However, in this case the through wire interconnects 14 on three ofthe semiconductor components 92 are stacked in a three die stack. Inaddition, the three die stack is bonded to the bumped semiconductor die96. In the middle components 92, the bonding members 32 and the vias 28are centered on the substrate contacts 20 rather than being offset,substantially as previously described and shown in FIG. 3C.

Referring to FIG. 9, a four die RDL semiconductor component 138 issubstantially similar to the RDL CSP semiconductor component 130 (FIG.7). However, in this case the through wire interconnects 14 on twoadditional semiconductor components 92 are stacked to the semiconductorcomponent 92RDL in a three die stack substantially as described forsemiconductor component 136 (FIG. 8).

Referring to FIG. 10, a four die wire bonded FBGA semiconductorcomponent 136 is substantially similar to the wire bonded FBGAsemiconductor component 104 (FIG. 5). However, in this case the throughwire interconnects 14 on three of the semiconductor components 92 arestacked in a three die stack substantially as described forsemiconductor component 136 (FIG. 8). In addition, the three die stackis wire bonded to the package substrate 106.

Referring to FIG. 11, a four die flip chip bonded FBGA semiconductorcomponent 142 is substantially similar to the flip chip bonded FBGAsemiconductor component 120 (FIG. 6). However, in this case the throughwire interconnects 14 on the stacked semiconductor components 92 arestacked substantially as described for semiconductor component 136 (FIG.8). In addition, the lowermost semiconductor component 92 is flip chipbonded to the package substrate 122.

Referring to FIG. 12, a face to face stacked semiconductor component 160is illustrated. The face to face stacked semiconductor component 160includes a pair of RDL semiconductor components 92RDL having the bondingmembers 32 of their through wire interconnects 14 bonded to one anotherin a face to face configuration. In addition, an underfill layer 162 isformed between the circuit sides 16 of the RDL semiconductor components92RDL for encapsulating and electrically insulating circuit sides andthe bonded bonding members 32. Further, terminal contacts 132 and RDLconductors 134 are formed on opposing back sides 18 of the RDLsemiconductor components 92RDL. The face to face stacked semiconductorcomponent 160 thus includes terminal contacts 132 on opposing sides,which permits stacking or surface mounting from either side.

Referring to FIG. 13, a back to back stacked semiconductor component 164is illustrated. The back to back stacked semiconductor component 164includes a pair of semiconductor components 92 having their back sides18 bonded to one another using a suitable adhesive or underfill layer,substantially as previously described for the underfill layer 162 inFIG. 12. In addition, the ball contacts 64 on the wires 30 of thethrough wire interconnects 14 of the semiconductor components 92, arebonded to one another using a suitable bonding technique, such as a goldto gold diffusion bond substantially as previously described. Further,terminal contacts 132 and RDL conductors 134 are formed on the circuitsides 16 of the semiconductor components 92 in electrical communicationwith the wires 30 of the through wire interconnects 14. In thisembodiment, the bonding members 32 are omitted, but could also beincluded, and placed in electrical communication with the RDL conductors134 and the terminal contacts 132. The back to back stackedsemiconductor component 164 thus includes terminal contacts 132 onopposing sides, which permits stacking or surface mounting from eitherside.

Referring to FIG. 14, a system 144 for forming the through wireinterconnect 14 in accordance with the method is illustrated. The system144 includes the semiconductor substrate 12 and the substrate contact 20on the substrate 12. The system 144 also includes an etching system 146configured to form the via 28 through the substrate contact 20 and partway through the substrate 12. The system 144 also includes a ventforming system 148 such as a laser machining system or an etching systemconfigured to form the vent 50. The system 144 also includes the wirebonder 52 configured to form the contact ball 64, to place the wire 30in the via 28 and to form the bonded connection 42 between the wire 30and the substrate contact 20. The system 144 also includes a dielectricdispensing system 154, such as a material dispensing system or screenprinter, configured to dispense the dielectric material 36 into the via28. The system 144 also includes a bonding member forming system 152,such as a stud bumper or a ball bonder, configured to form the bondingmember 32 on the wire 30 and the substrate contact 20. The system 144also includes a thinning system 150, such as a chemical mechanicalplanarization (CMP) system or etching system, configured to thin thesubstrate 12 from the backside 18 to expose the via 28 and the contactball 64.

Thus the invention provides improved semiconductor components, andmethods and systems for fabricating the semiconductor components. Whilethe invention has been described with reference to certain preferredembodiments, as will be apparent to those skilled in the art, certainchanges and modifications can be made without departing from the scopeof the invention as defined by the following claims.

1. A semiconductor component comprising: a first semiconductorsubstrate; and a second semiconductor substrate stacked on the firstsubstrate, each semiconductor substrate having a first side, a secondside, a substrate contact on the first side in electrical communicationwith integrated circuits, and a via extending through the substratecontact from the first side to the second side; each semiconductorsubstrate having a through wire interconnect comprising a compressedwire in the via, a contact on the wire proximate to the second side, abonded connection between the wire and the substrate contact and abonding member bonded to the wire and to the substrate contact; thethrough wire interconnect on the first semiconductor substrate bonded tothe through wire interconnect on the second semiconductor substrate. 2.The semiconductor component of claim 1 wherein the substrate contactcomprises a pad having a selected width and a selected length.
 3. Thesemiconductor component of claim 1 further comprising a conductor on thefirst semiconductor substrate in electrical communication with thethrough wire interconnect on the first semiconductor substrate and aterminal contact on the first semiconductor substrate in electricalcommunication with the conductor.
 4. The semiconductor component ofclaim 1 further comprising a conductor on the second semiconductorsubstrate in electrical communication with the through wire interconnecton the second semiconductor substrate and a terminal contact on thesecond semiconductor substrate in electrical communication with theconductor.
 5. The semiconductor component of claim 1 further comprisinga third semiconductor substrate stacked on the second semiconductorsubstrate having a second through wire interconnect bonded to thethrough wire interconnect on the second semiconductor substrate.
 6. Thesemiconductor component of claim 1 wherein the contact on the throughwire interconnect on the first semiconductor substrate is bonded to thecontact on the through wire interconnect on the second semiconductorsubstrate.
 7. A semiconductor component comprising: a firstsemiconductor substrate comprising a plurality of first substratecontacts having a plurality of first through wire interconnects; and asecond semiconductor substrate stacked on the first semiconductorsubstrate, the second semiconductor substrate comprising a plurality ofsecond substrate contacts comprising a plurality of second through wireinterconnects, each first through wire interconnect and each secondthrough wire interconnect comprising a via through a substrate contact,a compressed wire in the via, a contact on the wire in the via, a bondedconnection between the wire and the substrate contact, and a bondingmember on the wire and the substrate contact.
 8. The semiconductorcomponent of claim 7 wherein the bonded connection on the firstsemiconductor component is bonded to the bonded connection on the secondsemiconductor component.
 9. The semiconductor component of claim 7wherein the contact on the first semiconductor component is bonded tothe bonded connection on the second semiconductor component.
 10. Thesemiconductor component of claim 7 wherein the contact on the firstsemiconductor component is bonded to the contact on the secondsemiconductor component.